Tool with releasably mounted self-clamping cutting head

Abstract

A metal cutting tool has a cutting head releasably mounted on a front end of a tool shank, in a self-clamping manner. The tool shank's forward end is provided with a pair of shank coupling portions, each having a forwardly facing shank support surface. A pocket recess is defined between the shank's coupling portions. Within the pocket recess are a plurality of shank fixation surfaces which are parallel to a longitudinal axis of the tool shank. The cutting head has a cap portion and a fixation portion extending in rearward direction therefrom. The cap portion includes a pair of head segments, each having a rearwardly facing head base surface. The cutting head's fixation portion has a plurality of head fixation surfaces which are parallel to a longitudinal axis of the cutting head. In the assembled tool, the tool shank's forwardly facing shank support surfaces support the cutting head's rearwardly facing head base surfaces, while the plurality of head fixation surfaces abut the plurality of shank fixation surfaces.

What is claimed is: 
     
       1. A metal cutting head having a cutting head longitudinal axis (L) defining forward and rearward directions, the metal cutting head comprising:
 a cap portion comprising a plurality of head segments separated by at least first and second head flutes, each head segment comprising a rearwardly facing head base surface formed at a rearward end of the cap portion; and 
 a fixation portion joined to the cap portion and extending in a rearward direction of the cutting head, the fixation portion comprising:
 a mounting stem connected to the cap portion and a plurality of circumferentially spaced apart protrusions on the mounting stem; 
 wherein a plurality of spaced apart head fixation surfaces are formed on the fixation portion, each head fixation surface being parallel to the cutting head longitudinal axis and configured to apply a radially outward force when the metal cutting head is mounted; and 
 wherein the circumferentially spaced apart protrusions are distinct from the spaced apart head fixation surfaces. 
 
 
     
     
       2. The metal cutting head according to  claim 1 , wherein:
 the protrusions define a maximum dimension of the fixation portion in a direction perpendicular to the cutting head longitudinal axis. 
 
     
     
       3. The metal cutting head according to  claim 1 , wherein:
 each head fixation surface has an arcuate shape in a cross-section taken perpendicular to the cutting head longitudinal axis. 
 
     
     
       4. The metal cutting head according to  claim 1 , wherein:
 the protrusions are formed on a lower end of the mounting stem; and 
 each protrusion is provided with a beveled protrusion surface which forms a lower surface of the protrusion. 
 
     
     
       5. The metal cutting head according to  claim 4 , wherein:
 the beveled protrusion surface extends from a radially outward position to a radially inward position, in a rearward direction of the cutting head. 
 
     
     
       6. A metal cutting tool comprising:
 a metal cutting head releasably mounted on a forward end of a tool shank, the metal cutting head and the tool shank having a common axis of rotation and a common direction of rotation, wherein: 
 the metal cutting head comprises:
 a cutting head longitudinal axis (L) which is coincident with the common axis of rotation; 
 a cap portion comprising a plurality of head segments separated by at least first and second head flutes, each head segment comprising a rearwardly facing head base surface formed at a rearward end of the cap portion; and 
 a fixation portion joined to the cap portion and extending in a rearward direction of the cutting head, the fixation portion comprising:
 a mounting stem connected to the cap portion and plurality of circumferentially spaced apart protrusions on the mounting stem; 
 wherein a plurality of spaced apart head fixation surfaces are formed on the fixation portion, each head fixation surface being parallel to the cutting head longitudinal axis; and 
 wherein the circumferentially spaced apart protrusions are distinct from the spaced apart head fixation surfaces; and 
 
 
 the tool shank comprises:
 a shank longitudinal axis (S) which is coincident with the common axis of rotation; 
 a plurality of shank coupling portions, equal in number to the plurality of head segments, formed at the forward end of the tool shank, and a shank pocket recess formed between the shank coupling portions, each shank coupling portion including:
 a forwardly facing shank support surface; and 
 an inner surface comprising a plurality shank fixation surfaces, each shank fixation surface being parallel to the shank longitudinal axis; 
 
 
 wherein: 
 the rearwardly facing head base surface of each head segment is supported by the forwardly facing shank support surface of a corresponding shank coupling portion; 
 each head fixation surface abuts an opposing shank fixation surface over an abutment region; 
 the protrusions define a maximum dimension of the fixation portion in a direction perpendicular to the cutting head longitudinal axis and 
 the protrusions are spaced apart from walls of the shank pocket recess. 
 
     
     
       7. The metal cutting tool according to  claim 6 , wherein:
 the tool shank further comprises:
 a protuberance protruding forwardly from each shank support surface, the protuberance having a protuberance forward surface; and 
 a shank torque transmission wall extending along a portion of the protuberance transverse to the shank support surface and generally facing the direction of rotation; 
 
 the cutting head further comprises:
 at least one circumferentially facing head torque transmission wall extending generally transversely to the head base surface and generally facing opposite the direction of rotation; and 
 
 the shank torque transmission wall abuts the head torque transmission wall. 
 
     
     
       8. The metal cutting tool according to  claim 7 , wherein:
 the protuberance forward surface is generally parallel to the shank support surface. 
 
     
     
       9. The metal cutting tool according to  claim 6 , wherein:
 the plurality of circumferentially spaced apart protrusions are formed on a lower end of the mounting stem. 
 
     
     
       10. The metal cutting tool according to  claim 6 , wherein:
 the tool shank further comprises at least first and second shank flutes; 
 the head flutes and the shank flutes are generally aligned; and 
 adjacent the shank flutes there is a gap between the head and shank fixation surfaces of opposing pairs of head and shank fixation surfaces. 
 
     
     
       11. A metal cutting head having a cutting head longitudinal axis (L) defining forward and rearward directions, the metal cutting head comprising:
 a cap portion comprising a plurality of head segments separated by at least first and second head flutes, each head segment comprising a rearwardly facing head base surface formed at a rearward end of the cap portion; and 
 a fixation portion joined to the cap portion and extending in a rearward direction of the cutting head, the fixation portion comprising:
 a mounting stem connected to the cap portion and a plurality of circumferentially spaced apart protrusions on the mounting stem; 
 wherein a plurality of spaced apart head fixation surfaces are formed on the fixation portion, each head fixation surface being parallel to the cutting head longitudinal axis and configured such that, in any cross-section taken perpendicular to the longitudinal axis and passing through the head fixation surfaces, the head fixation surfaces are the radially outermost surfaces; and 
 wherein the circumferentially spaced apart protrusions are distinct from the spaced apart head fixation surfaces. 
 
 
     
     
       12. The metal cutting head according to  claim 11 , wherein:
 the protrusions define a maximum dimension of the fixation portion in a direction perpendicular to the cutting head longitudinal axis. 
 
     
     
       13. The metal cutting head according to  claim 11 , wherein:
 each head fixation surface has an arcuate shape in a cross-section taken perpendicular to the cutting head longitudinal axis. 
 
     
     
       14. The metal cutting head according to  claim 11 , wherein:
 the protrusions are formed on a lower end of the mounting stem; and 
 each protrusion is provided with a beveled protrusion surface which forms a lower surface of the protrusion. 
 
     
     
       15. The metal cutting head according to  claim 14 , wherein:
 the beveled protrusion surface extends from a radially outward position to a radially inward position, in a rearward direction of the cutting head. 
 
     
     
       16. The metal cutting head according to  claim 11 , wherein:
 the beveled protrusion surface extends from a radially outward position to a radially inward position, in a rearward direction of the cutting head.